1. ## determine the quadrant in which an angle lies. help!

hello u math brainiacs i need help!

how do i go about determining which quadrant the angle lies in?

ex) -5pi/6 please explain thoroughly so i can take notes and as easy as possible because i tried and cant figure it out.

thanks!

2. ## Re: determine the quadrant in which an angle lies. help!

Originally Posted by noork85
how do i go about determining which quadrant the angle lies in? ex) -5pi/6
$\displaystyle \frac{-5\pi}{6}$ is equivalent to $\displaystyle \frac{-5\pi}{6}+2\pi=\frac{7 pi}{6}$.
$\displaystyle \frac{7 pi}{6}\in III$ WHY?

3. ## Re: determine the quadrant in which an angle lies. help!

so thats it? just find the equivalent and then locate that equivalentbon on the unit circle?

4. ## Re: determine the quadrant in which an angle lies. help!

and what about -11pi/9 i got the answer as 7pi/9 cant locate that on the unit circle...

5. ## Re: determine the quadrant in which an angle lies. help!

Originally Posted by noork85
and what about -11pi/9 i got the answer as 7pi/9 cant locate that on the unit circle...
Well $\displaystyle \frac{1}{2}<\frac{7}{9}<1$ so it is in II.

6. ## Re: determine the quadrant in which an angle lies. help!

i understand what ur saying.

what about when im given something like just 3.5?

7. ## Re: determine the quadrant in which an angle lies. help!

Originally Posted by noork85
i understand what ur saying.
what about when im given something like just 3.5?
If $\displaystyle \pi<3.5<\frac{3\pi}{2}$ in it is in III.

8. ## Re: determine the quadrant in which an angle lies. help!

yes, ofcourse. y didnt i see that? thank you very very much!